The findings used prospective data (following persons over time) of 7,172 black Seventh-day Adventists participating in Adventist Health Study-2. Adventists are a Protestant religious group that promotes vegetarianism and advocates abstinence from tobacco and alcohol, which results in less confounding (distortions) when studying associations between diet and disease. Participants were given a questionnaire that asked how often they consumed 130 foods and food groups. Participants were then categorized into a dietary category (vegan, lacto-ovo vegetarian, etc.) based on their responses.
The study also analyzed data of 34,215 non-black Adventists and found similar protections against diabetes for a vegetarian diet. These findings confirm results from past cross-sectional research (examining persons at one point in time) that showed a vegetarian diet offered protection against diabetes.
Source: Loma Linda University Adventist Health Sciences Center